US1881685A - Phase shifting device - Google Patents

Description

oct. 11, 1932. y

' W. A. KNooP PHASE SHIFTING DEVICE Filed April 18, 1931 /NVENTOP W. A KNOOP W ATTORNEY mmmm x Q tok 1C.

DEEE

m m Ummm Patented 0.111, 1932 f VUNITED "sTATEs lPAJLEN'FI OFFICE g yWILLIAM:l A. 'KNOOP, OF HEMISTEAD, NEW YORK, ASSIGNOR T0 BELL TELEPHONE LABORATORIES, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK PHASE SHIFTING DEVICE This inventionrelates to a phase shifting device for use in an vimpulse transmission systemV employing synchronously rotating distributing devices. It is particularly useful in high speed printing telegraph systems. An object ofthe invention is to facilitate the phase adjustment of synchronously driven rotary distributing d-evices.

f 'A more specific object oti the invention is to establish proper phase relation between a continuously rotating receiving impulse distributing device Vand incoming signal impulses. Y v

In high speed telegraph systems employing long loaded submarine cables, synchronism between rotary distributors at opposite ends of the cable is maintained by utilizing signal impulsesto operate corrector circuits.

"320 These corrector circuits are arranged to correct thev distributor at the receiving end of the cable either by mechanical means, such' as disclosed in G. A. Locke, U. S. Patent No. 1,670,461, issued May 22, 1928, or by continu- Q5 ous electrical means, such as disclosed in U. S. Patent 1,848,180 granted to W. A. Knoop on March 8, y1982. The correction thus effected in both disclosures is gradual and is highly desirable when the receiving i) distributor is in approximate phase with the incoming signals. However, at the. beginning of a transmission period, particularly after a period of non-use, itmight be necessary to orient the receiving rings which are usually orientable with respect to the other rings onv theV same distributor, through a considerable arc to obtain `an approximate phase relation with the incoming signals. The lamount of orientation may be determined by means of a series of lamps which may be temporarily connected to the receiving distributors as shown in A. M. Curtis Patent 1,689,828, issued October 30, 1928.

According to the present invention the phase relation between the receiving dis- -tributor and the incoming signals is established in an eXpeditious and eiiicient manner by arranging intermediate the receiving distributor and the printers or lamps a cornmutator device iXedly mounted on a rota- 1931. Serial No. 531,107.

table shaft. The shaft has also tixedly mounted thereon a series of rings which are insulated from each other and the shaft. Each of the rings is electrically connected in iixed relation to one segment or bar of the l55 commutator. Individual brushes connect the segments of the receiving distributor with the insulated rings and other individual brushes connect the commutator bars with the phasing lamps or the selector magnets of the printers. In this way, connections through the commutator may be varied at will by rotating the commutator in either direction to change lthe positions of the H brushes with respect to the receiving seg-* yments and lamps, thereby obtaining the desired phase relation as indicated byV the lamps. A switch is provided for disconnecting the lampsy and for connecting`the printers after the phase relationV is obtained. Y"7'0 A better understanding of the invention will be had from the lfollowing detailed description and appendedV claims when taken in conjunction with the accompanying, drawing of which,

Fig. 1 shows a schematic circuit arrangement of the invention, and

Fig. 2 represents an assembly of the commutator adapted for use in Fig. 1.

Like :reference characters represent like` arts. p Referring to Fig. 1 signal impulses originating at a distant transmitting station Y are impressed over a transmission line 12, onto aHAL continuous ring13 of the receiving distribu- "85 tor 14 at station X. The distributor 14 comprises, in addition to continuous-ring 13, a segmented ring 15 and a rotatable brush 16. The distributor shown provides for receiving signals over four channels of transmission, but it is understood that the distributor may be designed to provide for a greater or a lesser number of chanrtels. Furthermore, the distributor provides to receive signals iny accordance with the Baudot or tive-unit impulse code, although it is also understood that the distributor is not to be limited to this particular code.

Inasmuch as the distributor shown in Fig. 100

Allis designed for four channels, the ring contains fort-y segments, that is, ten for each channel. Alternate segments are fixedly connected to brushes 171and the remaining segments are left dead. Should the brush 16 be ini, phase with the incoming signal impulses, it will be 'passing over-one of the segments connected to a brush 17 at the timey the .middle portionof agunitlength impulse is` impressed *o'njther ring. 13.Y lThis phase relaj `tionis known inthe art-as the true'phase in contradistinction to the approximatephase which will be hereinafter described. 'The segments connected to brushes 17 will be here- Y `inafter referred to as live segments.

Then 1t is-desired to transmitsignals, vpar- VVticularly aftera-period of non-use, as forexample, at the beginning of a days' run, it is usually the practice, first,'to establish approximatephase between the distributors at opposite ends of the transmission'line. Ac-

'cordingly, the receiving ring` set, such'as'ring set ll-,is made-orientable with respect tothe 4may, be rotated at will ineitherdirection by means-of -a hand-'knob 22, the amount of rotationY being indicated by' Vwheel 23 and pointer 24. FiXedly, but insulatively,mount ed on shaft '19 and in parallel'V relation with .the.- commutator ringV 18 are twenty individual slip rings 25 which are respectively y positioned in engagement with ybrushes 17. The commutator ring 18 is dividedinto twenltysegments'or bars to correspond to thenumber of slip Vrings and these bars are Vrespec- "tif-vely `connected in fixed relation tothe slip rings 'by means .of vconductors 26 (.Fig. 1).

' yFixedly positioned in l.engageable' relation fwiththe twenty .bars of commutator ringV V18 lare'vtwenty 'brushes l27 which are fixedly, `but 'insulati-*Vely* mounted lon some Apart of the base structure Y (not shown), supporting the standards 20'a'n'd 21. The brushes 27 are respectively connected by conductors 28 to contacts 29 of gang switchbar 30, which` is arranged to 'be operated rby hand' to connect. kryeither theprinters 31, 32, 33 and 34, corre- :spending respectively Vto the four channels, A lor the lamps '35v to the receiving circuit, the lamps 35 serving to indicate the phase relaationbefore the printers are connected.

remaining nineteen lamps. shown-herein, lamp 3"(V is selected to havethe transparent red cap, it being the third lamp in channel D. If the system is insynchron- `ous` phase, then, during `each revolution of fbrush 16,'red'lamp will light and the two :adjacent .lamps on `each side of it, that' is, .the first, second, fourth and Vfifth lamps of Operation of the system In multiplex transmission systems, particularly where transmission is over a long subf marine cable, and wherein polar signals are 'employed the polarity ofthe marking and spacing 'impulses are rreverse'dat the. end of each channel. When it is'desired to st art op- 'eration after a period ofnon-use, phasing signals are transmitted by'each of the transmitters,"in1turn, at station Y. :These signals may be constituted of various combinations of .impulses of positive and' negativeV polari-v ties. For the purpose of illustration, it is assumedthat lifnthe'first channel, say channel yA.,.the first, second, fourth-and iifthimpulses are of positive polarity andthe third impulse is negative; in the second channels, say channel. B, all the five impulsesA are of negative polarity; in the third channel, say channelC, all the five impulsesare of positive polarity; and in thefourthchannel, Saychannel D, the first, second, Vfourth and lifthim'pulsesare of negative polarity-and thethi'rd impulse is of positive polarity. The lamps 35 at station X are shown connected tothe negative pole of grounded battery 36.

If the receiving `distributor brush is, in synchronous phase with .the incoming signals, it will cause, yas it passes over each of the live segments of ring 15, amomentary Qlightingof the first, second, fourth and fifth Y'lamps v'of clianne'lfA, all the five .lampsfof j'chann'el C, andthe third lamp of channel D. "The remaining lamps which' receive from their respectively associated live7 segments,

impulses of negative polarity, will not light `beca-use of like polarities atopposite ends oftheir circuits.

'Howevenfafter a period of n on-use, synchronous' phase as setforth above, is rarely had, and therefore, it is necessary thatthe Y system be adjusted to establish what is known as approximate phase, before the transmission of message signals begins. .This-is acl"complished providing one lamp withsome suitable means such as a transparent red cap, which will be easily "distinguished from the In the system channel '1), iwill not light. If this condition is not had, as is usually the case, then the commutator 'ring 18 maybe rotated by turning knob 22 in either direction until the desired .condition is obtained. i

The system `is then adjusted for truc synchronous phase, that is, vthe condition wherein the live segments are positioned'to :re-

ceive-the middle portion, respectively, ofthe.

kas

incoming impulses. This adjustment is made by orienting the ring set 14, as is well known in the art, through a small arc. The range of orientation required is at the most a little more than the length of a full signal impulse. In a four-channel system, such as shown herein, this range would be a little more than 18, say, 27 or 30. This allows the exact positioning of the receiving segment with respect to the incoming signals without moving the ring set 14 through such a range as to break the leads.

The purpose of the true phase adjustment may be better understood by referring to the segment of channel D' shown on ring 15. I-Iere are shown in dotted lines three possible positions of the incoming impulse with respect to the third live segment of the channel, which may be obtained by the approximate phasing adjustment. The impulse in its eX- treme left-hand position which is designated a, is received partly on the second and the third live segments, the middle or effective portion being received on the dead segments between them. However, the portion received on the third segment may be of sufficient strength to cause lamp 37 to flash. Then again the impulse may be received in its extreme right-hand position, designated b, wherein the impulse is distributed over the third and fourth live segments and the dead segments between them. In either of these positions there might be suicient portions of the impulse received on the third segment to cause lamp 37 to flash. Therefore it is necessary that a further adjustment be made to shift the ring set 14 sufficiently in one or the other direction until the impulse is received in the position designated c, wherein the middle portion is received wholly on the third live segment. The means for making the last mentioned adjustment is well known in the art. It is therefore seen that the adjustment for true vsynchronous phase is limited to an angular distance of a little more than 18 for a four-channel system.

-What is claimed is:

1. In an impulse transmission system, a phase shifting device comprising individual means for receiving individual impulses, elements for indicating indivdual impulses, and manually operated means electrically connected intermediate said individual means and said elements, arranged to change the connection of each of the individual means from one of said elements to another.

2. In an impulse transmission system comprising means for receiving impulses over a plurality of channels, a plurality of means for respectively recording groups of impulses received over said plurality of channels, means for indicating the phase relation between incoming impulses and said recording l means, normally stationary means interconnecting said receiving means and said indil eating means comprising a circuit interlchanger arranged to be manually rotated to obtain any desired phase relation between the received impulses and said indicating means, and means for connecting to said receiving means the said recording means, in place of said indicatin means, when the desired phase relation 1s obtained.

3. In an impulse transmission system, according to claim 2, wherein the normally stationary means is a rotatable commutator device comprising a shaft, a ring constituted of insulated segments and fixedly mounted on said shaft, a plurality of insulated slip rings arranged in parallel to said segmented ring and fiXedly mounted on said shaft, individual electrical connections between said slip rings and said segments, and stationary brushes arranged in engageable relation with each of said slip rings and said segments.

4. In an impulse transmission system according to claim 2, wherein an indicator is provided on said normally stationary means for indicating the amount of rotation given thereto to establish the desired phase relation.

5. In an impulse transmission system, a

hasel shifting device comprising a distributing device for receiving line impulses, individual means for indicating said received impulses, a rotatable shaft having insulatively mounted thereon and insulated from each other a plurality of members in engagement with a plurality of elements, respectively, on said distributing device, a second distributing device ixedly mounted on said shaft, a plurality of contact elements insulatively mounted on said second distributing device and electrically connected in fixed relation to said plurality of members, respectively, and a plurality of elements for maintaining each of said contact elements in connection with one of said indicating lamps, said shaft being rotatable in either direction to change the connections between said contact elements and said indicating means as desired.

In Witness whereof, I hereunto subscribe my name this 15th day of April, 1931.

WILLIAM A. KNOOP.

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